(a) Field of the Invention
The invention is related to machines in injection molding and die casting, and is especially related to a method for core pulling and insertion in synchronization with the opening and closing of the mold as well as the apparatus to realize the said method in the molding process.
(b) Description of the Prior Art
The core pulling and insertion method and device used in the injection molding and die casting production process have been through changes. The conventional core pulling and insertion method for injection molding adopts a leaning guide post core pulling and insertion method, whereof as the leaning guide post has a longer translation distance in working but has a shorter stroke in actual core pulling and insertion due to its inherited structure, lowering work effectiveness and increasing cost. Hence, based on this, a method such as the mold external hydraulic/pneumatic cylinder actuated core pulling and insertion is employed as an improvement, similar to this technology includes the publicized application of the Chinese patent no. 200510049399.3′ A demolding device for the mold with a side core extraction and extrusion mechanism which discloses that the top of the fixing plate at one side of the mold is installed with a hydraulic cylinder which is through the work table of the press or injection molding machine to allow the piston rod of the said hydraulic cylinder to connect with the mold push rod, so that the said push rod is independently controlled by the installed hydraulic cylinder instead of interlinking with the work table of the press; thereby it effectively resolves the shortened stroke of molding core pulling and insertion problem and also has a higher work effectiveness compared with the afore mentioned technology. Nonetheless, both of the said methods have a the same imperfection, i.e. the opening and closing of the mold as well as the core pulling and insertion are separate actions which can only be operated manually, and due to inadequacy of automation, mis-operation may occur easily to damage the molds. Therefore, they shall be replaced, and a method and device for the molding core pulling and insertion with a higher degree of automation is urgently needed to be researched and developed for the replacement. The above said two methods of existing arts have another imperfection of unable to randomly set the stroke of core pulling and insertion according to requirement of workpiece that needs to be further improved.